1. Field of the Invention
This invention relates to diagnostic apparatus for diagnosing the location and the size of living tissues, particularly of cancer tissues, with laser light irradiation, and relates to medical treatment apparatus for treating the tissues on the basis of information detected from the diagnostic system.
2. Prior Art
In order to carry out medical treatments for cancer tissues, thermal therapies and laser-chemical therapies with laser light have been commonly utilized. In order to perform these therapies efficiently, it is important to detect precisely the information about the cancer tissues such as its location, and its size.
It is known that, when the laser light is irradiated against the cancer tissues, characteristic fluorescene is emitted from the cancer tissues and that, when a photo-reactant (hematoporphyrin derivative, pheophobide A etc.) is absorbed into the cancer tissues, other characteristic fluorescence is emitted from the cancer tissues. Therefore, the tissues emitting the fluorescence should be detected as the cancer tissues in order to know the information of the cancer tissues for carrying out effectively the medical treatment for the cancer tissues.
In the prior art, for detecting and diagnosing the cancer tissues, argon-dye laser light operated in a continuous wave mode is irradiated against the target area of the living tissues with a high output power level of about 200 MW in an irradiating system. A reflective wave from the cancer tissues is detected by means of a spectroscope in a detecting system, which is provided separately from the irradiating system.
However, this conventional method has the following problems.
First, in order to detect the size of the cancer tissues, the laser light should be irradiated against the tissues including the boundary portion between normal tissues and the cancer tissues as well as the cancer tissues themselves. Accordingly, by the laser light irradiation with high output power level, the normal tissues are often damaged.
Next, if enough of the characteristic fluorescence was emitted, the diagnosis of the cancer tissues could be carried out efficiently. However, from the boundary portion of the cancer tissues, not enough fluorescence is emitted. Further, noise produced in an emission lamp is mixed into the laser light emitted from a laser light generator. Thus, the laser light containing the noise is irradiated against the cancer tissues. Accordingly, the reflected wave from the tissues can not show the information of the tissues precisely. As shown in FIG. 3, which is a graphical view of the spectrum of the reflected wave from the cancer tissues with this conventional method, the spectrum having the wavelength of 670 nm produced by the fluorescence emission of the cancer tissues could not be detected at all. That is to say, although this conventional method can be performed theoretically, it can not be utilized practically because of the small amount of the fluorescence emission from the boundary portion and the mixing of the noise into the laser light.
On the other hand, the reflected wave might be amplified so that the spectrum having the wavelength of 670 nm produced by the fluorescence emission of the cancer tissues can be detected. However, according to the study of the inventor, in this case, it is also impossible to eliminate the influence of the noise to the spectrum.